The present disclosure relates to a display input device including a display unit and a touch panel. In addition, the present disclosure relates to an image forming apparatus including this display input device.
The display input device may be attached to an apparatus or equipment. The display input device enables setting and input of characters. Further, because the number of hardware keys arranged on a cellular phone terminal or the like is limited, a plurality of roles (meanings) may be assigned to one key. Therefore, a process assigned to a key in a current state may be unknown resulting in an input error or an increase of the number of times of pressing keys. In order to prevent this deterioration of operability, there is known the following technique.
Specifically, there is known an input device equipped with an input unit for inputting a press of a key as an execution instruction of a process assigned to the key, a long press detection unit for detecting a long press state in which a key is continuously pressed, and an informing unit for informing a user of a process assigned to the key while inhibiting an input by the input unit when the long press state of the key is detected. With this structure, it is aimed to enable the user to easily check a process assigned to each key.
An image forming apparatus such as a copier, a multifunction peripheral, a printer, or a FAX apparatus may also be equipped with a display input device (which may be referred to also as an “operation panel”). Further, the operation panel of the image forming apparatus displays a screen for selecting a set item or for setting a set value. Because there are many selectable set items and settable set values, a plurality of (many) types of screens are prepared.
Specifically, when a user wants to set a certain set value, a highest layer screen in a hierarchical structure is displayed first. Then, a button (key) for selecting a set item (classification or category) is operated on the screen (a display position thereof is touched) so that a next layer (next lower layer) screen is displayed. Further, as necessary, a button that can lead to a desired screen among buttons in the screen after the switching (buttons for selecting further lower layer set items) is operated. Then, the screen further moves to a next lower layer. Such button selection is repeated until reaching a desired screen. In other words, in order to reach a desired screen, it is required to repeat the operation on buttons so as to trace an appropriate path toward a lower layer screen one by one. In this way, displays on the operation panel have a hierarchical structure (or a tree structure).
Conventionally, in order to switch the display screen, it is necessary to actually operate a button in the screen. In other words, the screen is not switched unless a display position of a button is not touched. Therefore, in order to check a lower layer screen apart by a plurality of layers, it is necessary to actually press buttons in screens a plurality of times so as to switch the screen. Therefore, there is a problem that it is difficult to easily check which screen belongs toward a lower layer. In particular, a screen belonging to a layer lower than the current layer apart by two or more layers cannot be checked by one operation, and needs to repeat operation of a plurality of buttons to check repeatedly. In addition, when the switched screen is not a desired screen, an operation to return to the original screen is required. Therefore, there is a case where a long time and many operations are necessary to reach a desired screen for setting a set value.
In addition, in order to complete setting of the image forming apparatus, it may be necessary to move toward a lower layer screen apart by many layers (for setting about system, for example). In this case, screen transition (switch toward a lower layer screen) is repeated. In addition, there is a case where because a desired screen is in a deep layer, a path to the desired screen cannot be easily found, and transition to an incorrect screen and returning operation are repeated. In addition, there is also a problem that repetition of the screen switching and the returning operation may make it difficult to understand which layer is the current layer.
Here, in the cellular phone terminal described above, a function (process) assigned to the long-pressed key is displayed. However, though the assigned function is displayed, a screen to be displayed cannot be checked unless a button is actually pressed. In addition, in order to move the layers of display screens, it is necessary to operate a button every time, and a screen apart by a plurality of layers cannot be checked by one operation. In addition, repetition of pressing an incorrect key and returning operation afterwards may make it difficult to understand which layer is the current layer.